American writers are getting more comfortable with being funny about the Holocaust. This is a tricky business, of course — there's a fine line between irreverent and offensive. But it can be done: Novelists such as Tova Reich and Shalom Auslander have delivered witty, nervy books on the subject. Add to their ranks Boris Fishman, whose smart debut novel, "A Replacement Life," turns on a young man who becomes a semiprofessional liar about the death camps.

That man is Slava, who at first seems to arrive direct from New York-debut-novel central casting. He toils at an unprestigious job at a prestigious magazine, writing nutrient-free blurbicles that mock stories in flyover-country newspapers. He's unlucky in love, and unhappy about his stalled career.

So far, so post-collegiate. But the bustle and banter of his Russian Jewish family in Brooklyn gives this familiar character new life. Early on, Slava's grandfather asks him to invent a story about his family's Holocaust experience in order to receive restitution funds from the German government. Slava is aghast, but grandfather has cynical logic on his side. "This country does not invent things?" he asks. "When the stocks fall down, it's not because someone invented the numbers?"

Thus browbeaten, Slava uses his journalistic talents to spin a family narrative that withholds just enough information to be credible. And soon enough, the Brooklyn Jewish diaspora is beating a path to his door. It's a comic setup, but it works because Fishman humanizes the participants so well. Contemporary novelists have a bad habit of making immigrants appear monolithically earthy and good-natured, but Fishman knows better. As Slava visits a Russian bakery, he observes: "He eavesdropped on the conversations in line, Ukrainian if the g's were uttered like h's, Georgian if they emphasized the wrong vowel. These unlike people had been tossed together like salad by the cupidity of the Soviet government."

It gives nothing away to say that Slava eventually has to reckon with his deceptions. And if you know your New York debut novels, you'll be unsurprised to hear that Slava has a romantic conflict, too — whom shall he choose, the fetching fact-checker, or the girl from the old country? Underneath those familiar plot lines, though, are some spiky provocations about what kind of suffering deserves restitution, and how storytelling can paper over reality. "I can imagine myself as the person who's forging," Slava says. "But I can also imagine myself as the person who turns in the forger. How can that be?" Fishman's novel is a deft and funny exploration of the answer.